Jeff Horwitt: A majority of Republican primary voters believe that if no one wins enough delegates to secure the nomination before the convention, the candidate with the most votes in the primaries should be the nominee.

Republican Sen. Rand Paul is choosing Valentine’s Day to take a jab at Hillary Clinton. On Saturday morning, the senator’s Facebook page posted a message saying that “if Hillary Clinton set up a Pinterest page, we can only imagine it might look like this.” It included links to a mock profile on the photo-sharing site set up under Mrs. Clinton’s...